Method of manufacturing boxes



Jan. 12, 1954 Filed May 10, 1952 T. JUNGMAYR METHOD OF MANUFACTURINGBOXES l/I I v2 Sheets-Sheet 1 Fig.1

, Ina 72R may! Jaw 14 METHOD OF MANUFACTURING BOXES Filed May 10; 1952 2Sheets-Sheet 2 MWf WPR 7950301? Juli/6M4? Patented Jan. 12, 1954 UNITEDSTATES PATENT OFFICE 2,665,616 METHOD OF MANUFACTURING BOXES Theodor: Jungmayr, Stuttgart, Germany Application May 10, 1952, Serial No. 287,165

" 1 Claim. (01. 9345.1)

This invention relates to containers or boxes of the type consisting ofa shell or casing and end plates inserted therein and provided withupwardly flanged borders or tabs, and to a method of manufacturing suchcontainers. The invention has special reference to boxes of the type inwhich the end of the casing which by corner incisions is also formedwith borders or tabs is inwardly turned, in a U-shape, over the edges ofthe borders of the end plate which has been inserted into the casing bya corresponding amount, and joined to the inner side of the upturnedborders of the'end plates, the connection between the end plate and thecasing being effected by'bonding the borders of the end plates to thecasing.

It is the object of the present invention to provide-a container of thetype referred to which can be manufactured very easily and without thedanger of tearing of the casing as the end plates are inserted.

Another object of the invention is to provide a container which isconstructed in ,such a way that a tight seal between the end plate andcasing parts are ensured.

With these objects in view, according to the present invention a softfoil which can be folded is used for sealing the closure, which foil isplaced and fixed on the blank of the end plate in such a way that itcovers the borders and the corner incisions between the borders and onupturning of the borders is also upturned with the formation of cornertips, so that on insertion of the end plate into the end of the casingof the box the edge or border of the foil will seal both the anglecorners and the butt joints of the borders as well as their foldingedges. The corner tips of the foil are joined to the borders and can bebonded thereto, if desired. However, the invention also offers thepossibility of making the sealing foil of a thermoplastic material whichon application of heat and pressure permits a plastic deformation of theloose corner tips without any folds and thus ensures an absolutelyreliable sealing of the corners as well as a bond between the end platesand the casing. In this case it is also possible to dispense with theapplication of an adhesive on the casing and/or on the end plate,whereby a substantial simplification can be achieved in the manufactureof the boxes.

Other and further objects, features and advantages of the invention willbe pointed out hereinafter and. appear in the appended claim formingpart of the application.

In the accompanying drawings several now preferred embodiments of theinvention are shown by way of illustration and not by way of limitation.

Fig. 1 is a plan view of a blank of an end plate including the foilarranged thereunder,

Fig. 2 is a perspective view of an end plate with the foil, in anupwardly turned condition,

7 Fig. 3 is a perspective view of the end plate inserted in the casing,

Fig. 4 is a cross section showing the seal produced thereby,

Fig. 5 is a plan view showing a modified form of a blank of an end platewith foil,

Fig. 6 is a perspective view showing this end plate in an upwardlyturned condition of its border portions, 7

Fig. 7 is a perspective view showing the end plate inserted in thecasing, and r Fig. 8 is a section through the seal obtained in thiscase.

Similar reference numerals denote similar parts in the different views.

Referring now to the drawings in greater detail, and first to Fig. 1, itwill be seen that I is the end plate with cut-out corners 2 which arenot rounded, or only slightly rounded. These re-entering angles as wellas the borders of the blank are covered or overlapped by a sheet 3 of asoft foil material which can be folded and which is bonded to the blankI by an adhesive while the same is still in a flat condition. Before oron insertion of the end plate into the end of S at the neck corners ofthe end plate.

produced between Then the borders of the end of the shell on applicationof an adborders of the end plate, as shown in Fig. 4.

In the embodiment as per Fig. 5, if using a foil of a thermoplasticmaterial, it is not necessary to apply an adhesive on the tabs orborders of the shell, since the foil also serves as a bonding agentbetween the borders of the end plates and the borders of the shell. Tothis end according to Fig. the foil 3 on each side is formed with anextension I projecting over the borders of the end plate, the length ofthis portion 1 corresponding to that of the borders or tabs of theshell. Here again as shown in Fig. 6 before or on inserting the endplate into the end of the shell 8 the tabs together with the borders ofthe foil are upturned, the corners of the foil 3 forming tips 4projecting inwards through the gaps between the tabs of the end platesand being put on the upwardly turned tabs, as shown in Fig. '7. Now thetabs of the shell 8 are folded inwardly about the edges of the tabs ofthe end plate, as shown in Fig. 8, whereby the extensions '1 of the foil3 come to lie between the tabs of the end plate and the tabs of theshell. By application of heat and pressure the tabs of the end platesare bonded both with the shell and with the turned over tabs of theshell. For heating the foils radiating heat, preferably electrical heat,is used.

The process can also be carried out in such a way that the tips 4 formedby the corners of the foil extend outwardly and are turned against thetabs from outside.

The box may consist, for instance, of paper, cardboard or any othersheet material which can be folded. The thermoplastic foil may consist,for instance, of polyvinyl compounds, cellulose derivatives or othersynthetic materials.

While the invention has been described in detail with respect to certainnow preferred examples and embodiments of the invention, it will be,understood by those skilled in the art after understanding the inventionthat various changes and modifications may be made without departingfrom the spirit and scope of the invention, and it is intended,therefore, to cover all such changes and modifications in the appendedclaim.

What is claimed is:

A method of producing boxes from a casing blank and a closure blank, theclosure blank having foldable borders and being formed with cornercut-outs, and having a foil of foldable material attached thereto, saidfoil having extending portions projecting beyond the corner cut-outs andcovering the same, comprising; upturning the borders of the closureblank to form a tray with said extending foil portions formingprojecting corner tips while dividing said extending foil portions toproject inwardly of the tray and between the edges of the cut-outs ofthe closure blank to form inwardly projecting tips; holding theprojecting corner tips against adjacent upturned borders of the closureblank; inserting the thus produced and erected closure into one end ofthe casing blank; folding edge portions of the casing blank about theborders of the end closure and over the folded corner tips; and joiningthe edge portions of the casing blank to the borders.

THEODOR J UNGMAYR.

References Cited in the file Of this patent UNITED STATES PATENTS NumberName Date 726,205 Tuttle Apr. 21, 1903 737,692 Alger Sept. 1, 19031,455,321 Case et a1. May 15, 1923 2,409,460 Waters Oct. 15, 1946FOREIGN PATENTS Number Country Date 324,383 Great Britain Jan. 27, 1930366,194 Great Britain Feb. 4, 1932

